1. Technical Field
This disclosure relates to computer numerical control (CNC) manufacturing in general, and, more particularly, to CNC additive manufacturing.
2. Description of Related Art
Most current additive manufacturing (AM) processes are layer-based. By converting a three-dimensional model into two-dimensional layers, the process planning can be dramatically simplified. However, there are also drawbacks associated with such an approach such as inconsistent material properties and difficulty in embedding existing components.
FIG. 1 illustrates a beam structure (a) and a comparison of a prior art additive manufacture process (b) with that of an exemplary process according to the present invention (c). Such an AM process according to the invention can provide for improved building speed and/or improved material properties of the built structure(s) when compared to layered approaches, as will be described in further detail below.
For example, a three-dimensional (3D) beam AB in a beam structure as shown in FIG. 1(a) is first sliced into a set of two-dimensional (2D) layers; a physical model can then be built by stacking all the layers, referring to FIG. 1(b). A significant benefit of the layer-based approach is that, by converting 3D geometry into 2D contours, its process planning is dramatically simplified. However, there are also drawbacks associated with the layer-based approach. For example, beam AB will have different material property depending on its building orientation.
Another drawback of the layer-based AM processes is the limitation on the allowable motions between the tools and the work pieces, which are mainly translational motions in X, Y, and Z axes. Consequently, embedding existing components (i.e. building around inserts) in the processes is usually difficult.